A Core for production of VRP and recombinant proteins is proposed for three reasons. First, although production of VRP with the bipartite RNA helper system has reduced the generation of propagation-competent virus by RNA recombination to undetectable levels (a frequency of <l0-10), CDC-NIH guidelines require Biosafety level 3 containment for the packaging of VEE replicon RNAs and subsequent testing of the VRP preparations for infectious virus. Such a facility has been in operation under the supervision of Drs. Johnston and Davis at UNC for the last 10 years. Second, experiments proposed for Projects 1-3 will require some of the same VRPs and recombinant proteins. A core facility will provide efficiency and economies of scale through centralized production. Third, a concerted effort can be made in this Core to optimize the conditions for VRP and recombinant protein production to benefit all three Projects.